To change the Air filter
Looking at your engine on the right side you will see a round air box with a big tube coming out of it. There are a few screws you can remove and the air filter is right under it. Refer to you Honda manual.
There are pics and instructions how to change it.

The cabin air filter is under your glove box.
Open your glove box. Empty it. There are two black latches on each side. Take those out and the glove box will fold down. Behind it you will see the fan system for your A/C. The filter is in that unit. There is a rectangular shaped cover that you undo and pull out. The filter is attached to it.
Replace and reinstall.
The Honda manual pics and instructions for this also.
Good luck